MIT's New Liquid Flow Batteries Could Make Refueling EVs as Fast as Pumping Gas

A team of researchers at MIT set out to “reinvent the rechargeable battery” and succeeded by creating a liquid-flow battery, suitable for electric vehicles that can be recharged as quickly as simply pumping gas and could halve the cost of current EV batteries. The new batteries involve a semi-solid, liquid electrolyte material which holds suspended positive and negative electrodes that provide needed electricity. When all the energy has been zapped out of the amorphous material, you can simply remove it from the battery — recharge it for future use — and replace it with fully charged goo. The team at MIT envisions this happening in much the same way — and about the same amount of time — that we’re all used to pumping gas.

This kind of liquid flow battery is not new, but prior research teams were not able to find a material that had high enough energy density to make the batteries plausible. With lower energy density needed to make huge structures to hold the batteries, the MIT team has managed to find a material — shown above on the right — that ups the energy density of prior liquid flow batteries ten fold. This improvement made the structures small enough to be plausible for use in electric vehicles, large energy storage facilities as well as smaller applications.

The researchers came up with the idea for their liquid flow battery by combining the traditional positive and negative electrodes of a lithium-ion battery — now used in most electric vehicles — with the suspension ideas of a liquid flow battery. By suspending the positive and negative electrodes in the battery — in traditional lithium-ion batteries they are stationary — the team made it possible to replace the battery’s energy making system without having to recharge it within the batteries structure. By creating this new, less expensive design the research team believes they could bring down the cost of electric vehicles to make them more competitive with gas-powered vehicles.

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7 Comments

@ Sammael I believe that the number you’re quoting is actually ~500 Wh/L. Li-ion currently is struggling to go above 250 Wh/kg.

SammaelJune 7, 2011 at 7:26 pm

@lazyreader
ultracalacitors are quick to recharge, true, but even in lab conditions we only got them to 85 Wh/kg energy density, and that is many years from economic production. Highest available energy density is only 30 Wh/kg. LiIon batteries are already in range of over 500 Wh/kg.
On the other hand Lithium-Titanate quick charging battery has energy density of LiIon battery and ability to be recharged in 10 minutes on quick charging station.

lazyreaderJune 6, 2011 at 4:50 pm

What I meant to say was; Near future we may not even need to use batteries. What about ultracapacitors, flywheels or other options.

@caeman: Weren’t you the one calling electricity the opiate of the masses, and said we were not going to be able to do it.

materialsdaveJune 6, 2011 at 3:20 pm

If you’re interested in the science behind the story, we’ve made the original article available for free at http://mvie.ws/VJMVs .

Dave Flanagan
Advanced Materials

lazyreaderJune 6, 2011 at 1:10 pm

Don’t liquid batteries have the potential to leak? Wouldn’t solid batteries be better. Near future we might even use batteries, what about ultra-capacitors.

caemanJune 6, 2011 at 12:31 pm

Now we’re talking. If they can make this work, it removes the primary complaint against EVs that I and many others have. You fix that “stuck in the middle no where for 8 hours to recharge” time and I will buy an EV.